Re: [PATCH v11 00/15] khugepaged: mTHP support
From: Lorenzo Stoakes <hidden>
Date: 2025-09-15 11:24:52
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On Mon, Sep 15, 2025 at 01:14:32PM +0200, David Hildenbrand wrote:
On 15.09.25 13:02, Lorenzo Stoakes wrote:quoted
On Mon, Sep 15, 2025 at 12:52:03PM +0200, David Hildenbrand wrote:quoted
On 15.09.25 12:43, Lorenzo Stoakes wrote:quoted
On Mon, Sep 15, 2025 at 12:22:07PM +0200, David Hildenbrand wrote:quoted
0 -> ~100% used (~0% none) 1 -> ~50% used (~50% none) 2 -> ~25% used (~75% none) 3 -> ~12.5% used (~87.5% none) 4 -> ~11.25% used (~88,75% none) ... 10 -> ~0% used (~100% none)Oh and shouldn't this be inverted? 0 eagerness = we eat up all none PTE entries? Isn't that pretty eager? :P 10 eagerness = we aren't eager to eat up none PTE entries at all? Or am I being dumb here?Good question. For swappiness it's: 0 -> no swap (conservative) So intuitively I assumed: 0 -> no pte_none (conservative) You're the native speaker, so you tell me :)To me this is about 'eagerness to consume empty PTE entries' so 10 is more eager, 0 is not eager at all, i.e. inversion of what you suggest :)Just so we are on the same page: it is about "eagerness to collapse", right? Wouldn't a 0 mean "I am not eager, I will not waste any memory, I am very careful and bail out on any pte_none" vs. 10 meaning "I am very eager, I will collapse no matter what I find in the page table, waste as much memory as I want"?
Yeah, this is my understanding of your scale, or is my understanding also inverted? :) Right now it's: eagerness max_ptes_none 0 -> 511 ... 10 -> 0 Right? So we're saying, currently, 0 means 'I will tolerate up to 511 pte_none, and eat them all I am very very eager', and 10 means 'I will not tolerate any pte_none' right? Correct me if I'm wrong here! :>)
-- Cheers David / dhildenb
Cheers, Lorenzo